Global application configuration

[This](https://facebookmicrosites.github.io/bpf/blog/2020/02/20/bcc-to-libbpf-howto-guide.html#application-configuration) article section describes how globals can be used to configure a BPF program before loading. I'm curious if we could have some helpers for setting some simple configurations from Go. For my use case, I want to configure a single uint32, for which an entire map and the lookup overhead seem a little drastic. Any ideas on how we could maybe achieve this?

@yanivagman @eyakubovich @grantseltzer

Start with the linked article's application-configuration section and inspect how libbpfgo currently loads BPF programs from Go. Determine the intended helper API for setting simple globals before loading, using a single uint32 as the concrete case. Done should include an agreed approach and corresponding Go support without requiring a full map for that configuration.

Written by the indexing model from the issue text.